Index

Risk of Diesel Pollution; Avoid Traffic Congestion

Advertisement

Diesel exhaust contributes significantly to the U.S. ambient air pollution burden. This form of air pollution is the product of diesel fuel combustion, commonly generated by buses, trucks, trains and ferries. The particles can remain airborne for extended time periods, and travel long distances prior to being inhaled.

Advertisement

Nationwide, particulate matter and especially the fine particles such as those in diesel exhaust cause 15,000 premature deaths every year. In general, children are more sensitive to air pollution because they breathe 50 percent more air per pound of body weight than do adults. Diesel exhaust also contributes to ozone formation (a component of smog), acid rain, and global climate change.

Breathing polluted air, especially smoky exhaust that billows from factory smokestacks and the tailpipes of some diesel-powered buses and trucks, is bad for people with heart disease, about three times more likely to have ischemia (decreased oxygen supply to heart muscle) during exercise testing; according to the first study of its kind reported in today’s rapid access issue of Circulation: Journal of the American Heart Association.

A recent report from the American Cancer Society study cohort found that long-term exposure to fine particulate air pollution at levels that occur in North America increased the risk for cardiovascular mortality. The risk increased by 12 percent for every 10-micrograms-per-1-cubic-meter-of-air elevation in fine particle concentration. Congestion in the air and on the ground is a major pollution producing problem. At peak times, aircraft queue to land, take-off and berth. Such delays mean planes must carry more fuel and greater weight than they otherwise would.

Researchers from the Harvard School of Public Health and colleagues assessed the effect of high air pollution levels, specifically emissions from coal-burning power plants and diesel vehicles, on Boston-area adults with diabetes. Their study found that on days when air pollution levels were high, adults with diabetes were at higher risk for cardiovascular problems due to impairments in blood vessel function.

There may be an association between traffic-related air pollution and allergic rhinitis. Some experts believe that refined fossil fuels, such as diesel fuel and particularly kerosene, are important triggers for allergic rhinitis. In people who already have allergies or asthma, exposure to such fossil fuels may worsen symptoms.

A study by the air sampling confirmed that diesel pollution from the countless vehicles involved in the recovery and rebuilding effort is heavily concentrated downtown. Samples of the study were collected and analyzed. The levels of sulfur, which indicates the presence of diesel pollution, were much higher than at uptown sites. The emissions from diesel engines also cause fine particle and ozone formation.

"Although the average Los Angeles driver spends about six percent (1.5 hours) of his or her day on the road, that period of time accounts for 33 to 45 percent of total exposure to diesel and ultra fine particles (UFP), according to the study published in the journal Atmospheric Environment. Ultra fine particles are of particular concern because, unlike larger particles, they can penetrate cell walls and disperse throughout the body, Fruin says. Particulate matter has been linked to cardiovascular disease, but the ultra fine fraction on roadways appears to be more toxic than larger sizes.

A new UCLA study linking diesel exhaust to atherosclerosis, or hardening of the arteries, which significantly increases one's risk for heart attack and stroke. Fine particles in air pollution conspire with artery-clogging fats to switch on the genes that cause blood vessel inflammation and lead to cardiovascular disease.

Another studu by Dr. Mills at the Centre for Cardiovascular Science, University of Edinburgh shown that "brief exposure to dilute diesel exhaust promotes myocardial ischemia and inhibits endogenous fibrinolytic capacity in men with stable coronary heart disease". Same like study by Cardiovascular Epidemiology Research Unit, Boston concluded that the risk of having an acute cardiovascular event triggered by vigorous exertion may be heightened with exposure to high levels of air pollution; the risk–benefit ratio may be optimized if people exercise away from traffic when possible.

Inhaling diesel exhaust fumes causes changes in the body that may make people more prone to heart attack or stroke, researchers said on recently.European scientists found that blood clots are more likely to form in otherwise healthy people exposed to relatively high amounts of diesel engine exhaust for a short time. This could cause a blocked vessel, heart attack or stroke.

The British and Swedish scientists said they did not know if the findings from their small study would be the same with exhaust from gasoline-powered engines. Diesel engines spew many times more fine pollutant particles than gasoline engines. Based on the findings, they recommended that people with heart and artery disease exercise away from traffic congestion to avoid the effects of this pollution.

"The important long-term aims of research like this are to try to promote changes in public health initiatives," said Dr. Andrew Lucking of Britain's University of Edinburgh, one of the researchers in the study presented at a meeting of the American Heart Association in Orlando.

Lucking said the researchers plan to test devices called particle traps that could be retrofitted on diesel engines to reduce diesel particles. The study involved 20 healthy men, ages 21 to 44. They breathed filtered air and also diluted diesel exhaust at a level approximating curbside exposure on a busy road.

Compared to breathing filtered air, breathing air with the diesel exhaust increased clot formation roughly 20 percent to 25 percent in the hours after exposure. The researchers also found an increase in platelet activation in the blood. Platelets play a main role in clotting.

Dr. Daniel Jones, president of the American Heart Association, said, "The evidence for air pollution and cardiovascular disease being related is growing. It appears to be real. What we don't understand are some of the exact causal mechanisms.” In September the same group reported in the New England Journal of Medicine that heart attack victims showed clear differences when breathing diesel fumes. They found the hearts of heart attack survivors were far more likely to be starved of oxygen when exercising while breathing in such fumes that when exercising in clear air.

A number of studies show increased incidence of cancer (lung, skin, and urinary cancers) in humans exposed to mixtures of polycyclic aromatic hydrocarbons (PAHs). The primary source of PAHs is from burning carbon containing compounds. PAHs in air are produced by burning wood and fuel for homes. They are also contained in gasoline and diesel exhaust, soot, coke, cigar and cigarette smoke, and charcoal-broiled foods.

A study by the University of Edinburgh and UMEA University found that inhalation of diesel exhaust caused changes in the heart's electrical activity, suggesting that air pollution reduces the amount of oxygen available to the heart during exercise. This study provides an explanation for why patients with heart disease are more likely to be admitted to hospital on days in which air pollution levels are increased.

People with asthma because of the particulates - minute particles of dust, dirt, soot and smoke - which they release into the air. Particulates come in different sizes but those of less than 2.5 microns, and the tiniest "ultra fine" ones, can interfere with the respiratory system, because they are so tiny that they can be inhaled deeply into the lungs.

"The fumes from burning fuels, including diesel, contributes to pollution and can cause heart disease, bronchitis and asthma. Efforts are underway to replace petrol and diesel with cleaner biofuels, such as biodiesel, but there is considerable resistance to this". Researchers at Deakin University stated that "study provides clear evidence that diesel exhaust is more harmful to our health than biodiesel exhaust."

Alternative fuel might be ethanol which is produced domestically from corn and other crops and produces less greenhouse gas emissions than conventional fuels. Biodiesel is derived from vegetable oils and animal fats. It usually produces less air pollutants than petroleum-based diesel. Natural gas is a fossil fuel that generates less air pollutants and greenhouse gases. Hydrogen can be produced domestically from fossil fuels (such as coal), nuclear power, or renewable resources, such as hydropower. Fuel cell vehicles powered by pure hydrogen emit no harmful air pollutants.

People who are sensitive to particle pollution can reduce their health risks by cutting back on strenuous activities or scheduling strenuous activities when air quality is better. Air Quality Index will be an even better resource for millions of Americans to manage their health.

So question arises whether diesel fuel releases high levels of particulates into the air, and there research has shown there is a strong connection between the contaminant and cancer. Environmental pollutants such as diesel exhaust, ozone and nitrogen dioxide are leading causes of chronic coughing in both children and adults. What’s being done to lessen the tremendous health risk from school bus diesel exhaust to the 24 million kids across the nation who rides school buses every day?